Rotary piston engine

ABSTRACT

A rotary piston engine comprises an annular circular-sectioned cylinder, a working piston and a contra-piston both part annular and circular-sectioned and both mounted for rotation in said cylinder, a chamber defined in said cylinder, between said pistons constituting a working chamber of the engine and undergoing cycle changes in volume during rotation of said pistons.

O United States Patent 1191 1111 3,724,428

Mederer 1 1 Apr. 3, 1973 54 ROTARY PISTON ENGINE 2,142,706 1/1939Wolstenholme ..418/33 1,299,588 4/1919 Luikart ..418/33 [76] InventGerhard Am 1,981,615 11/1934 Enderlin ..123/8.47 8501 Anefsberg, Germany2,840,058 6/1958 Stringer ..l23/8.47 22 Filed: May 2 1971 2,270,9761/1942 Sobek ..418/37 X PP N05 1471899 Primary Examiner-Allan D.Herrmann Attorneyl(enwood Ross [30] Foreign Application Priority DataABSTRACT June 3, 1970 Germany ..P 20 27 109.4

A rotary piston engine comprises an annular clrcularsectioned cylinder,a working piston and a contra- (g1 ..123/8;1(;72, piston both p annularand circulabsectioned and both mounted for rotation in Said cylinder, achamber [58] Field of Search ..123/8.47,418/33,36, 37 defined in saidcylinder, between Said pistons com [56] References Cited stituting aworking chamber of the engine and undergoing cycle changes in volumeduring rotation of UNITED STATES PATENTS Said p 3,552,363 1/1971Funakoshi ..418/33 X 3 Claims, 5 Drawing Figures PATENTEDAPR 3 ms SHEET1 0F 5 INVENTOR. GERHARD MEDERER lwzwwd Chem/z 9 m ATTORNEYS.

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ROTARY PISTON ENGINE This invention relates to a rotary piston engine.An object of the present invention is to provide a rotary pistoninternal-combustion engine which is compact and can give highperformance and have a high compression ratio.

Accordingly the invention provides a rotary piston engine comprising anannular circular-sectioned cylinder, a part-annular working pistondisposed in the cylinder and drivingly connected to an output shaft, acontra-piston also disposed in the cylinder for following the workingpiston at a distance which varies during working of the engine andautomatic device for adjusting the distance between the working pistonand the contra-piston being provided, and the chamber defined betweenthe pistons varying during working of the engine so as to constitute aworking chamber of the engine which undergoes cycle changes in sizeduring working of the engine.

The annular cylinder and the part-annular working piston andcontra-piston, revolving therein, enabling the engine to be of simpleconstruction and simple in operation. Such operation is easy to controland observe or monitor.

During revolving of the working piston and the contra-piston thechambers occassioned by the spacing of the two pistons are constantlyshifted circumferentially of the annular cylinder, the device foradjusting the spacing between the pistons effecting a change in the sizeof the chamber during rotation. The control device is effective toensure that the chamber is greatest in size for intake of fuel or airand becomes smaller during subsequent compression and has its smallestvalue at the ignition point. Here at the point of greatest compressionis present, the ignition then ensues. Ignition can be effected by aspark plug in the case of a fuel/air mixture or can be be injection ofdiesel fuel in the case of an engine working on the diesel cycle. Theexpanding combustion gases bring about an increase in the spacingbetween the pistons, by the working piston moving in a forward directionaway from the contrapiston, the development of a useful torque at anoutput shaft of the engine. After a short angular movement of theworking piston, expulsion of spent combustion gases occurs and, onfurther movement of the pistons enlargement of the chamber and intake offurther fuel/air mixture or air into the chamber for the next workingcycle. When the pistons have passed the intake region on their path ofmovement, the mutual spacing of the pistons is reduced, so that the airor fuel/air mixture is compressed. The mutual piston spacing is at itssmallest in the ignition region and so here maximum compression occurs.The working cycle is then repeated.

For transfer of the rotary force from the working piston to the outputshaft and for the mounting thereof as well as for incorporation of thepiston-spacing control device it is advisable to provide in the spaceenclosed by the ring cylinder a hollow circular disc, the sides of whichare attached, at their centers to the output shaft, the working pistonbeing connected securely to the hollow circular disc and there beingprovided, outside the hollow space in the circular disc and concentrictherewith, bearing discs which are supported for output shaft, thecomponent parts of the control device for adjusting the spacing betweenthe pistons being accommodated in the hollow space of the circular disc.Preferably the hollow circular circular disc is composed of two discsspaced apart by a distance piece connected securely to the workingpiston and securely to the discs.

In order to mount the contra-piston for movement in the cylinder and forvarying of the spacing between the pistons, in a preferred embodiment ofthe invention, the contra-piston is fastened to a U-section slidingrail, which is pivotally linked to a first lever, which is pivotallyconnected to a circular disc, which is mounted for rotation on aneccentric of a shaft, which is itself mounted for rotation in thebearing discs and is connected securely to a pinion which meshes with astationary counter-pinion fixed to the output shaft, the circular discbeing guided frontally in circular recesses in the side wall of thehollow circular disc.

If the pinion and counter-pinion have the same number of teeth oneignition ensues for each complete rotation of the working piston andcontra-piston. The number of ignitions during one revolution can easilybe altered by varying the transmission ratio between the pinion and thecounter-pinion.

A high compression ratio, which can be between 1:10 and 1:40, becomespossible because the working piston and the contra-piston have theiropposed faces lying in respective radially extending planes.

The invention will be described further, by way of example, withreference to the accompanying drawings wherein:

FIG. 1 is a longitudinal section through a preferred embodiment ofrotary piston engine conforming to the invention;

FIG. 2 is a section along the line IIII of FIG. 1;

FIG. 3 is a section along the line IIIIII of FIG. 1',

FIG. 4 is a section along the line IVIV of FIG. 1;

FIG. 5 is a section along the line VV of FIG. 1.

A preferred embodiment of rotary piston engine conforming to theinvention comprises a working piston 1 (FIG. 2) which is part-annularand mounted for rotation in an annular cylinder 2. The working piston 1is connected securely to an annular distance piece 3, which isaccommodated in a slot dis posed inwardly of the cylinder 2. Circulardiscs 4, 4' are arranged on both sides of the distance piece 3. Thesediscs 4, 4' are connected, for example by pins or bolts 5, to thedistance piece 3. The discs 4, 4' and the annular distance piece 3 forma circular disc having a hollow interior space 6.

The discs 4, 4' are connected, by their outer sides 7, 7 to two shaftparts 8, 8' which together form an output shaft of the engine. Theseshaft parts 8, 8' are mounted for rotation in bearing discs 9, 9', whichbutt for sliding movement against the outer sides 7, 7 and are supportedby ball bearings 10, 10' on the cylinder 2 The shaft parts 8, 8penetrate counter-pinions 13, 13 which are fastened stationarily to theengine housing and which mesh with pinions I2, 12. The counter pinions13, 13' are mounted in the housing, and a flywheel 14 is fastened on theshaft part 8 via which the power delivery is effected.

The contra-piston 15 is mounted for rotational movement behind theworking piston 1 with a variable spacing A between them in the cylinder2. The contrapiston is fastened to a U-section sliding rail 16, whoselimbs 17, 18 embrace the hollow disc 3, 4, 4 for sliding movement. Thesliding rail 16 is linked via a pivot consisting of a pin 19 and a bush20 to a lever 21, which is mounted for swinging movement at 22 in a nose23 fixed to an eccentric 24. The central point of the eccentric 24,which is circular, lies at 25. The eccentric 24 is mounted for rotarymovement on a circular shaped eccentric 26, which is mounted fixedly onboth sides, to the shaft 27, the shaft 27 being mounted in the bearingdiscs 9, 9' and securely carrying the pinions 12, 12'.

The opposed surfaces 28, 29, of the pistons 1 and 15 are flat, i.e.,they extend as radial planes. The spacing A is at its minimum in theposition, shown in FIG. 2, and at this position the volume of thechamber30 bounded by the pistons 1 and 15 has been brought to its minimumvalue, fuel/air mixture or air present in this chamber is at its highestdegree of compression. The fuel/air mixture can now be ignited by aspark or diesel fuel injected to cause ignition. Upon ignition, thecontra-piston 15 remains initially at rest, held by the control device.On the other hand, the-working piston 1 is move by the expandingcombustion gases in the direction of the arrow B. As soon as the workingpiston 1 has arrived at a, the combustion gases can flow out via outletorifice 31; they are then completely expelled by the laggingcontra-piston 15. As soon as the working piston 1 has arrived at b, thesuction port 32 is freed, so that a fuel/air mixture, or air is suckedinto the now comparatively large chamber. When the working piston 1 hasarrived, at c, then the contra-piston 15 is moved faster than theworking piston, so that the fuel/air mixture or the air is compressed onthe path from c to d. As soon as the pistons are at the level d,ignition is effected once again and the working cycle repeated.

The eccentric disc 24 is mounted with a close fit in circular recesses33, 33 formed in the discs 4, 4' and can move slidingly in theserecesses. The nose 23 is kept narrower than the mutual spacing S of thediscs 4, 4' and extends into the hollow space 6.

When ignition is effected at the position shown in FIG. 2, a large forceis exerted on the opposed piston 15 in a direction opposite to that ofthe arrow B. Consequently there arises at the pin 19 a force P whichleads through the pivot point 22 and which endeavors to rotate the nose23 and eccentric 24 about the central point of the output shaft 8 whichis impossible because the eccentric 26 finds itself off-center in theeccentric 24. There thus arises at the point 34 a force R, effective inthe counter direction of rotation to the force I, about the centralpoint 35. From the torsional moments of the forces P and R about thecentral point 35 there results a residual torque in the direction of theforce R about the central point 35. The result of this is that theforce, acting in the opposite direction to the arrow B on thecontra-piston face 29 upon ignition, does not bring about any effectiveforce reduction. Moreover, a force V arises, which is directed upwardlyoff-center from the central point 35. This force V endeavors to turn thesystem anticlockwise. In other words a force V effective in theuseful-force direction of rotation also acts when ignition takes placeand is obtained from application of force on the contra-piston face 29.Upon ignition the contra-piston 15 initially remains almost at rest, sothat the working piston 1 is shifted in the direction of the arrow B andso enlargement of the chamber 30 occurs. On its path of revolution inthe direction of the arrow B, the working piston 1 entrains the discs 4,4 and therewith the eccentric 24 guided in the recesses 33, 33' thereof.Consequently the axis 34 of the shaft 27 is moved on a circular arc K ata spacing T in relation to the axis 35 of the output shaft 8. As thisoccurs, the pinions 12, 12' rolls on the counter pinions 13, 13' so thatthe eccentric 26 is rotated and therewith the lever 24 is swung with itsnose 23 and the pivot point 22. This effects a change in the spacing Aof the pistons 1 and 15, in such a way that the contra-piston runs fromthe ignition point d as far as the point c, where the compressionbegins, slightly more slowly than the working piston, but from c as faras d it runs more rapidly than the working piston, so that the spacing Aof the pistons increases between the ignition point at d and the pointc, but becomes smaller from c to d.

The number of ignitions upon one rotation of the pistons depends on thetransmission ratio of the toothing of pinions 12, 12 and counter pinions13, 13'. The design can readily be selected in such a way that two ormore ignitions are effected on one revolution. A prerequisite for thisis that an integral or whole-numbered transmission ratio is selected.

The ejection and intake of air or fuel/air mixture can, if need be, becontrolled via valves or slides. In the case of a fuel/air mixture,i.e., a petrol engine or gas engine an ignition plug can be situated inthe working piston 1 or adjacent the point d. If air is compressed aninjection nozzle can be provided in the piston l or adjacent point d toinject diesel fuel to cause ignition by compression.

In the rotary piston engine of the invention, as in the case of theconventional reciprocating piston engine circular-sectioned pistons areused. The individual strokes of a working cycle are however noteffected, as in the case of the reciprocating piston engine, in the samechamber, a chamber instead, in effect, is assigned to each stroke whichchamber is formed, on the path of revolution at different points bymeans of the space in between the working piston and the contra-pistonin the cylinder.

With the engine of the invention a high compression ratio can beachieved, which is in addition variable, in that the spacing A can beadjusted. Despite the use of similar pistons as in the case of thereciprocating piston engine, a jamming of working and contra-pistoncannot occur in the engine of the invention. The number of revolutionscan be selected comparatively high. With small dimensions, acomparatively high performance is achieved. The efliciency of the engineis comparatively high.

The engine can compress a mixture of petrol or gas with air and ignitethis mixture, after compression, with a spark, or can compress air andinject diesel fuel to cause ignition by compression. The engine can thusbe a petrol or gas engine or a diesel engine. The engine can, of course,also work on the two-stroke principle. If inlet valves and operatingmechanisms are provided the engine can be a steam engine or a hot gasengine. Many other variations are, of course, possible.

I claim:

1. A rotary piston engine, comprising an annular circular-sectionedcylinder, a part-annular working piston disposed in the cylinder anddrivingly connected to an output shaft, a contra-piston disposed in thecylinder for following the working piston at a variable distance duringworking of the engine, the chamber defined between the pistonsconstituting a working chamber which undergoes cyclic changes in size, ahollow circular disc provided centrally of the cylinder with its sidesbeing centrally connected to parts of an output shaft, the workingpiston being connected securely to the disc, bearing discs supported forrotary movement and supporting the parts of the output shaft, means forcontrolling the spacing between the pistons, said controlling meanscomprising the contra-piston being 2. The engine as set forth in claim1, characterized in i that the pinion and counter-pinion have equalnumbers of teeth.

3. The engine as set forth in claim 2, characterized in that the numberof teeth on the pinion is an integral multiple of the number of teeth onthe counter-pinion.

1. A rotary piston engine, comprising an annular circularsectionedcylinder, a part-annular working piston disposed in the cylinder anddrivingly connected to an output shaft, a contrapiston disposed in thecylinder for following the working piston at a variable distance duringworking of the engine, the chamber defined between the pistonsconstituting a working chamber which undergoes cyclic changes in size, ahollow circular disc provided centrally of the cylinder with its sidesbeing centrally connected to parts of an output shaft, the workingpiston being connected securely to the disc, bearing discs supported forrotary movement and supporting the parts of the output shaft, means forcontrolling the spacing between the pistons, said controlling meanscomprising the contra-piston being fastened to a slide rail pivotallylinked to a lever pivotally connected to an eccentric disc mounted forrotary movement on an eccentric of a shaft mounted for rotary movementin the bearing discs and connected to a pinion meshing with a stationarycounter pinion penetrated by the output shaft, the eccentric disc beingguided in circular recesses in the side walls of the hollow circulardisc.
 2. The engine as set forth in claim 1, characterized in that thepinion and counter-pinion have equal numbers of teeth.
 3. The engine asset forth in claim 2, characterized in that the number of teeth on thepinion is an integral multiple of the number of teeth on thecounter-pinion.